Self-destruction fuze



Aug. 19,1947. F, B, WALLMgE' i2,425,769

SELFv DESTRUCTION FUZE Filed Sept. 14, 1944- 27 /3 Frank E Wallac-E l SELF-DESTRUCTION FUZE Frank B. Wallace, Phoenix, Ariz.

Application September 14, 1944, Serial No. 554,140 s claims. '(ol. 1oz- 71) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) The invention described herein may be manu- The chamber in the fuze body between the closfactured and used by or for the Government for ing disk 2 and the lower disk 3 contains a longigovernmental purposes without the payment to tudinally mounted firing pin 5. The ring pin 5 me of any royalty thereon. has one end suitably rounded or pointed, and is This invention relates to fuzes for projectiles. 5 slidably positioned so that its unpointed end is An object of the invention is to provide a fuze inserted into the cylindrical recess I9 in the which insures the self destruction oi the projecclosing disk 2, while its pointed end is inserted tile after it has traveled a predetermined time through the bore 22 in the lower disk 3 with the or distance Without having i'lrst been exploded by pointed end a short distance from the primer. A contact with a target. 10 coiled spring 'l presses against a collar I8 on the Another object of the invention is to provide a firing pin 5, thus urging the ring pin toward fuze which is so compact that it may be used the primer 2li in the recess 2li. A detent II restin the smaller sizes of projectiles in which little ing against the lower disk 3 holds lback the colspace is available for this purpose. lar I8 thus preventing the rilng pin 5 from con- Further objects will appear from the following tacting and exploding the primer 24. The shape description. of the detent II may also be seen in Fig. 3. Where projectiles are red at a target such as Detent II is provided with a bent leaf spring an airplane, and are designed to be exploded upon i@ fastened to it by means of a rivet I2 and striking the target, those projectiles which miss the spring, with one leg bearing against the side the target will fall to the ground and explode on of the ring pin 5, tends to urge the end of detent contact therewith, causing possible damage to Il adjacent '60 Collar I3 outwardly S0 that if the friendly personnel and properly. It therefore bedetent were not prevented from such movement comes necessary to equip the projectile with a said end would move to a position clear of collar detonati-ng device in addition to the percussion I3, allowing the spring 'l to push the collar and fuze, so that the projectile, having missed the hence the firing pin 5 to-ward the primer 24, dettarget, will explode before hitting the ground. onating it and exploding the projectile, This may take any one of several forms, and However, this is prevented by the stop lll which the present invention is believed to describe an here takes the form of an annular washer made eiective method. of a material which while dry has considerable A typical fuze according to the invention is strength but which becomes iiaccid when made illustrated in the drawings, in which: wet by a liquid. A spacing washer I5 separates Figure 1 is a longitudinal sectional view of the stop I4 from the lower disk 3. The washer I4 fuze, may be of paperboard, cardboard, or similar sub- Figure 2 is a vertical sectional view of the fuze stance and the wetting liquid water. The dimenalong the lines A-B, sions of the washer I4 will depend on the speed Figure 3 is a perspective view of the detent with which it is weakened by the action of the l l, and wetting liquid and the time at which the shell Figure 4 is a plan view of a blank from which is to explode after missing the target. The detent II may be formed. washer Ill may also be of Celluloid or other sim- Reference to the drawings shows a fuze body ilar material and the liquid a suitable solvent I having a longitudinal chamber, formed by consuch as acetone. Or an acid liquid may be used centric cylindrical bores of various diameters as with a washer of a material easily weakened by shown. In the nose end of the chamber is placed the acid. It is seen that there are many well a closing disk 2 fastened by crimping or other known combinations of washer material and liqsuitable means and at the tail end is a separable uid that may be employed to achieve the delower disk S provided with a central bore 22. The sired result. The liquid 26 is stored within an magazine 2| contains an annular recess 28 in annular hollow frangible capsule 6 made of clear which is placed a sensitive primer or percussion glass or other similar material, and positioned cap. The fuze as thus far described is adapted within the fuze as shown, its outside diameter to re the primer upon contact with a target and being such that it fits snugly into the chamber, thus detonate a powder train in theshell, causand its inside diameter large enough to clear the ing it to explode. If the shell does not hit a other parts of the fuze adjacent to it. The captarget, then it is still made toexplode before sule 6 rests against a felt washer 8 and is held hitting the ground by means of the rest of the in position by a coiled spring 9 which in turn construction shown. rests on the projection of washer Ill substantially Walls are thin enough to break when the shellris fired. While the force of setback on ring is normally sufficient to break the capsule 5, a lsharp pointed projection may be mounted on each of the weights I3 at the location 2'?, the points being long enough and so directedv as to engage and cut open the capsule 6 upon setback. This may be doneV by changing the outline of the blank shown in F'ig. 4 to make the angleat 'l'.acute. The detent l l is also provided with a bore .il .substantially greater in diameter than the firing pin 5, andthe edge lS-of thefbore H is rounded oil to prevent binding between the detent I l and-the ringj-pin at .the point of contact. The bore Il maybe formed by drilling two overlapping holes in z'the detent Il, so that the lo-Wer hole as seen in Fig, 2 is only slightly Ylarger than the firing pin .diameter while theupper overlapping hole is considerablvlarger. The result is that the remaining lowerarcof the'lower-hole forms a bearing surfacev at this point between the detent ll and the-firing pin 5, the spring l serving to keep the detentand firing pin incontact, and prevents sidewise movement offthe detent at this point. .Weights I3 are attached to the detent H to sub- .stantiallycounterbalance centrifugal forces rel sulting from rotation of the shell during night due to riling'of the 'gun barrel. The detent li including the weight portions I3v may be stamped and formedfrom asingle piecey of sheet metal if desired, as .shown in Figs. 3 and 4.

`Atypical cycle'of operation may now be described. The shell vis fired from the gun at a -target'which may bea-moving airplane. If the shell hits the target, the concussion resulting from :'impactfis transmitted through the fuze to the primer, causing the shell lto eXp-lode. It .should be noted that .the severe-.setback resulting-at ltheltime the gun is fired, is normally sufcient `to break the liquid containing frangible capsule 6 through theforceof inertia, causing theliquid to escapefrom the capsule and tosoak theswasher, M. The washer lll weakens or becomesfl-accid underthe .effect of the wetting. and by the time the ,shellhaspassed the target and is falling to `earth `thewasherhas beenso weakened Athat .it interposes little or no 4resistance tothe end. of the detent vl l, and .the spring Iitogether with any unbalanced centrifugal force, forces the` endv23 of the detent Il routwardly so thatit Clears the collar I8 which is thenpushed axially by the spring l, forcing the rfiring pin .5 against .the .prirn.er,. detonating it .and thus ve-X- ploding the shell in the` air'before it reaches the ground.

.While the description .shows a preferred form of the invention it is to be understood that numerous changes in the shape, size, materials and arrangement may be resorted to without departing from the spirit and scope of the invention as claimed hereinafter.

I claim:

1. A self destruction fuze for projectiles, comprising a primer, a spring actuated ring pin to detonate said primer, a detent normally holding said firing pin retracted, a stop normally holding said detent in place, said stop capable of becoming flaccid upon absorption of a liquid, spring meansbetween said firing pin and said detent for biasing the same away from said ring pin and against said stop, a liquid for making said stop accid whereby said spring means becomes operative to move said detent away from said firing pin torelease the .same for movement, a frangible container forsaid liquid, projecting means on said detent adapted to strike said frangible container on set back of same to break the same for releasing the liquid therein for contact with said stop.

2. A fuze for projectiles, comprising a primer, a spring pressed firing pin for exploding said primer, and having a collar an L-shaped detent for normally holding said firing pin retracted by bearing against said' collar, said detent having an aperture through its base through which .the lower portion of the ring pin passes and'of substantially larger diameter than said por-tion of the firing pin; a leaf spring mounted'on said de tent and urging it radially outward from the axis of said firing pin; weights mounted on the base of said detent to counter balance `the centrifugal forces of rotation; a stop holding vsaid detent against the collar on said firing pin, Asaid-stop capable of becoming-fiaccid upon absorption of a liquid; a liquid for'wetting said iibre-stopto.cause it ,to become accid; an annular lfrangilele container for said-liquid; and inertia operated means for freeing said liquid from said container and bringing it into Contact 'with said Vsoluble .fibre stop.

3. A fune according to claim 2 in Wh-ich the inertia operated means consists of sharp projections mounted on the counter weights on said detent against which ythe frangiblecontainer is broken by force of inertia upon setback.

FRANK B. WALLACE.

REFERENCES @ITED The following references are of record in the file of this patent:

Y UNITED STATES PATENTS Number Name Bate 2,314,678 Zint Mar. 23, :1943 1,337,525 lVicAlpine .Apr.'20, 1920 FOREIGN PATENTS Number VCountry Date 135,239 Great Britain Nov. 17, 1919 319,835 Germany Mar. 30, 1920 

